"Το μεσημεριανό αρχίζει σε λιγάκι."
Μετάφραση:Lunch starts in a minute.
Not for lunch, true, but for a movie, show, a lesson... Or "I'm doing that/ going there/ leaving (etc.) in a bit". I personally wouldn't say in greek "Lunch starts" at any time point! (Was your question about greek or the phrase itself? It looks weird to me in both languages but, if people say it in english, who am I to tell them to stop? :D )